Why we will never see fully autonomous commercial ships

The same fast-paced advances in technology that have led to projects to automate vehicles in every other sector of the transportation industry have also found their way to the shipping industry. Advances in camera technology, sensors, electromechanical actuators and satellite technology appear to promise a world in which ships will soon traverse the oceans without a human on board. International Maritime Organization (IMO) and the Comité Maritime International (CMI) are already exploring how autonomous vessels would fit into the existing framework of international maritime law.

Yet, while it is laudable to plan for the future, autonomous vessels operated by computers and remote operators quite simply pose too many vulnerabilities and they likely will prove too expensive to replace today’s manned vessels. The professional merchant mariners who operate ships today are the crucial on-scene decision makers, repairmen, and physical security providers who make commercial shipping secure, efficient and inexpensive.

One existing obstacle for automating larger vessels is battery technology. At the outset, today’s batteries simply do not have the energy density necessary to power larger commercial vessels. Higher capacity and more powerful electric batteries that are capable of moving larger ships will likely be developed in the future. However, current battery technology has limitations. Lithium ion batteries, the type used for automated vehicles and aircraft, can explode if overcharged and further, large lithium ion batteries need to be temperature controlled to work properly.

Even more challenging obstacles to the success of autonomous vessels will be the expense and complexity of designing such systems. The technical challenge of operating a large cargo ship autonomously on the open oceans for days or weeks at a time will require a command and control system that does not exist today and may be impractical to build.

Seamanship and navigating a ship safely is a challenge even with a full complement of crew members on board. Automated ships will require command centres, computers, advanced satellite communications systems, other electronic devices, remote operators and other technicians. Autonomous vessels would save money by not having a crew, but shipping companies will in many cases be simply replacing merchant mariners with other workers, most likely more expensive technical workers, who will work in offices on land or will be on call to assist autonomous ships across the oceans. Shipping companies will likely need multiple redundant command centers to provide the robust level of connectivity required for the safe and secure operation of these ships.

All of this advanced technology will be very expensive and much of the expense will be the cost of designing and operating a system capable of providing the propulsion, navigation controls, and stopping power necessary to operate a ship continuously in the harsh ocean environment. The weather, wind, waves, fog, obstructions, marine mammals, salt water, birds and other ships that vessels encounter mean an autonomous ship will require incredibly complex technology able to withstand the chaos of the ocean environment and enable a ship to respond remotely to any incident or emergency. It is still an open question whether today’s controls and communications technologies are sufficiently robust and capable so as to be relied on for commercial shipping in place of a human crew.

The most serious concern regarding autonomous vessels is the one that will very likely keep them from ever being employed: the risk of exploitation by adversaries, hackers, terrorists, criminals and other malign actors. Autonomous vessels’ dependence on the electromagnetic spectrum and cyberspace infrastructure coupled with the lack of any human on-scene responders will provide an opportunity for others to interfere with these ships and potentially use them as weapons or for profit. The challenge for system designers is that the characteristics or features that make an automated system feasible for commercial application, such as standardisation, continuous communications and periodic updates, also provide exploitable opportunities for bad actors. Autonomous commercial cargo vessels would provide too easy a target of opportunity for theft, misuse, interference, or worse.

Some reality must be injected into the debate over autonomous ships. It is a truism that electronic and mechanical systems will eventually fail. For vital applications where human lives are at risk such as for aircraft, system engineers design in wide tolerances, safeguards, and multiple levels of redundancy to ensure an adequate margin of safety. The challenge in designing autonomous vessels is building both a safe and secure system that will function effectively in all ocean and maritime conditions without human beings on board and one that is not capable of being exploited by bad actors. Such a system, even if possible in theory, would likely be too expensive for companies to build and operate compared to human crew. As a result, autonomous vessels are extremely unlikely to displace the human network of maritime professionals that have always made the maritime transportation system safe and secure.

Commander David Dubay is a Military Professor of International Law and Associate Director for the Law of Maritime Operations, Stockton Center for International Law, US Naval War College, Newport, Rhode Island. The views presented are those of the author and do not necessarily reflect the official policy or position of the US Navy, US Coast Guard, or the US Naval War College.